Model Paper 1 — BIOLOGY STD 12 Science — Question

Answer the following questions:
Explain the role of any two accessory glands in human male reproductive system.

A garden pea plant bearing terminal, violet flowers, when crossed with another pea plant bearing axial, violet flowers, produced axial, violet flower and axial, white flowers in the ratio of 3 : 1. Work out the cross showing the genotypes of the parent pea plants and their progeny.

Suggest some methods to assist infertile couples to have children.

What is menstrual cycle. Explain its various events with the help of diagram.###Describe in detail the various stages of menstrual cycle with the help of diagram.###Write a detail note on different stages of menstrual cycle and also sketch out these stages of
menstrual cycle by graphical diagram.###Define sexual reproduction. Explain the process of menstrual cycle.

Write the important characteristic of cromagnon man and also clarify that it was closest ancestor of modern man?

Explain the difference between the forward strand and lagging strand of DNA.

What do you mean by double fertilization ? Explain with the help of diagram.###Explain double fertilization.

(i) Define translation.
(ii) Explain the translation process.
(iii) Draw a labelled diagram of the translation.

In the medium where E. coli was growing. lactose was added, which induced the lac operon. Then, why does lac operon shut down some time after addition of lactose in the medium.

Elaborate how invasion by an alien species reduces the species diversity of an area.